前立腺癌診断における超音波パワードプラ下生検の役割

Abstract

1)血清PSA陽性者170名を対象に, power Doppler imaging(PDI)を検索し, 異常血流部位(HVL)が描出された68名にpower Doppler-guided prostatic biopsyを施行した. 2)HVLが描出された68例中, 40例に癌が検出された.またPSAグレーゾーン 107例中, 13例より, 癌が検出され, このうち12例はHVL陽性であった. 3)PDIのsensitivityは98%, specificityは71%, positive predictive value(PPV)は59%, negative predictive value(NPV)は99%であった.又, PSAグレーゾーン症例では, sensitivityは92%, specificityは79%, PPVは38%, NPVは99%であった

Between March 1997 and December 1998, a total of 170 cases with an abnormal serum prostate specific antigen (PSA) level (range: 4.1-200, mean: 20.5 +/- 31.0) were chosen for this study. Following the evaluation of the prostate using power Doppler imaging (PDI) with a 7.5 MHz transrectal probe, the hypervascular lesion (HVL) was biopsied transperineally under PDI real-time guidance. Thereafter, when gray-scale transrectal sonography revealed a hypoechoic lesion, additional samples were taken from them. Finally, sextant systematic biopsy was performed in all cases. Prostatic biopsy was positive for cancer in 41 cases (24%). The positive biopsy rate was 59% (40/68) in cases with HVL, compared to 1% (1/102) in cases with no HVL (p < 0.0001). In 107 patients with serum PSA 4.1 to 10.0 ng/ml, biopsy was positive in 13 cases (12%). The positive biopsy rate was 38% (12/32) in cases with HVL, compared to 1% (1/75) in cases with no HVL (p < 0.0001). These results imply that HVL represents the neovascularity or increased perfusion of blood in the cancer lesion. Power Doppler-guided prostatic biopsy could be promising as a new biopsy technique in patients with abnormal PSA levels including moderately elevated PSA levels (4.1-10.0 ng/ml).